Medical device with OLED illumination light source

ABSTRACT

A medical device such as a catheter or endoscope device includes an illumination light source having one or more organic light-emitting diodes (OLEDs). The OLEDs are energized to produce illumination light that is received by an image sensor or camera to produce images of tissue within a patient&#39;s body. A heat conductive polymer conducts heat away from the illumination light source.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.12/209,170, filed on Sep. 11, 2008, which is a divisional of U.S. patentapplication Ser. No. 10/737,980, filed Dec. 17, 2003, each of which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to medical devices in general, andilluminated catheters and endoscopes in particular.

BACKGROUND OF THE INVENTION

Many modern in-vivo medical devices such as catheters or endoscopes areequipped with imaging equipment that includes a light source and animage sensor. A light source delivers an illumination light onto an areaof interest while the image sensor obtains an image from the reflectedor scattered illumination light. The images obtained are used by aphysician to diagnose internal body tissue or to perform surgicalprocedures in the body.

The most common type of light sources used on catheters and endoscopesare lasers or high powered white light sources. Light from theseexternal light sources is delivered to the distal end of the scope by afiber-optic illumination channel. Alternatively, some devices have solidstate light sources such as light-emitting diodes (LEDs) that arelocated at or adjacent the distal tip of the device. Both approacheshave limitations. First, the optical fibers used to form an illuminationchannel are relatively fragile and limit the bending ability of thedevice. On the other hand, LEDs are often encapsulated in a plastic orother transparent material that is relatively large in comparison to thesize of the light-emitting element. Therefore, the amount of light thatcan be delivered at the distal end of the device is limited by thediameter of the device. Therefore, there is a need for a light-emittingdevice that can be incorporated into a medical device such as anendoscope that avoids these limitations.

SUMMARY OF THE INVENTION

To overcome the above-referenced limitations, the present invention is aflexible in-vivo medical imaging device such as a catheter or endoscope,having a light source made of one or more organic light-emitting diodes(OLEDs). An organic light-emitting diode is formed on the substratebetween two or more semi-transparent electrodes. The organiclight-emitting diode material produces illumination light whenelectrical energy is applied to the electrodes. The light source maycomprise an OLED of a single color. Alternatively, the light source maybe a stack or other configuration of OLEDs each having a differentillumination wavelength such that one or more OLEDs can be energized atthe same time to produce a desired illumination light. In anotherembodiment of the invention, the OLEDs are selected to produceexcitation light in the ultraviolet wavelength band for fluorescence ordrug-induced imaging. In yet another embodiment of the invention, theOLEDs produce light in the infrared range for tissue heating.

In one embodiment of the invention, the light source is sufficientlybright to allow external imaging devices to track the position of thelight source as it is moved in the patient's body.

In another embodiment of the invention, the OLEDs are formed as stripsthat extend along the length of the device. The strips have distancemarkings thereon to gauge how far the device has been inserted into thepatient.

In yet another embodiment of the invention, a catheter includes a heatconducting polymer to conduct heat away from the OLEDs and the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description, whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows a medical device such as an endoscope having a single OLEDlight source at or adjacent its distal end in accordance with oneembodiment of the present invention;

FIG. 2 illustrates a medical device having a light source comprising anumber of OLEDs;

FIG. 3 shows components of an in-vivo medical imaging system, includingan OLED light source in accordance with the present invention; and

FIG. 4 shows a medical device including a strip of OLED material thatcan be used to gauge depth of insertion into a patient in accordancewith another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As indicated above, the present invention is an in-vivo medical devicethat uses organic light-emitting diodes (OLEDs) as a light source toprovide illumination light within a patient's body cavity. FIG. 1 showsthe distal end of an in-vivo medical device 10 such as a catheter,endoscope, bronchoscope, trocar, guidewire or other device that isinserted into a patient's body cavity. At or adjacent the distal end ofthe device is the light source 12 having one or more organiclight-emitting diodes that produce illumination light when energized.

The light source 12 has a substrate 14 on which is formed an electrode16. A semi-transparent electrode 18 is formed on top of the organiclight-emitting diode material such that the diode material is sandwichedbetween the electrodes 16 and 18. Electrode wires, conductive leads, orother current carrying devices 28 connect the electrodes 16 and 18 to apower supply 30, which is typically external. However, the medicaldevice could have built-in batteries to power the light source. Theapplication of electrical energy to the electrodes 16 and 18 cause theorganic light-emitting diode material to produce illumination light. Thecomposition and method of constructing an OLED light source 12 suitablefor use with the medical device of the present invention are known tothose of ordinary skill in the art of light-emitting diodes. See, forexample, U.S. Pat. Nos. 6,627,333; 6,124,046; 6,127,693; and 6,495,198,which are herein incorporated by reference.

In the embodiment shown, the light source 12 is generally cylindrical ortubular in shape such that the medical device 10 can include one or moreparallel or coaxial lumens 22 extending through the light source 12. Inaddition, the medical device 10 may include an image sensor 24 at oradjacent its distal end for capturing images of a patient.Alternatively, the medical device 10 may include an imaging light guideand one or more lenses that direct reflected and back scatteredillumination light to an external image sensor or camera.

The illumination light provided by the light source 12 may be in thevisible, ultraviolet or infrared spectrum depending upon the desired useof the medical device 10.

FIG. 2 illustrates another embodiment of a medical device 50 having anOLED light source 52 at or adjacent its distal end. The light source 52includes a substrate 54 and a number of spaced, semi-transparentelectrodes 56, 58, 60, 62. Between the electrodes are segments oforganic light-emitting diode material of different colors or wavelengthsin order to form a stacked organic light-emitting diode (SOLED). Thecolor or illumination wavelength of the light induced by the lightsource 52 can be adjusted by applying a voltage to selected electrodes56, 58, 60 or 62. The SOLED can be manufactured with known lithographicor semiconductor fabrication techniques such as those described inPatent Application No. PCT/US98/01412, which is herein incorporated byreference.

In the embodiment shown in FIG. 2, the light source 52 has an ovoidalshape with an atraumatic distal tip to reduce the likelihood of damagingtissue in the body. The medical device 50 also has one or more lumens 70exiting the distal end of the device and an imaging sensor 72 forproducing images of the patient.

FIG. 3 shows an in-vivo medical imaging system including a medicaldevice 100 having a light source 102 formed of one or more OLEDs thatprovide illumination light to a point of interest in a patient's body.At the proximal end of the medical device 100 are the proximal openingsof one or more lumens within the medical device 100, through which aphysician can insert an instrument into the patient. In addition, theproximal end of the medical device includes a connector 109 thatconnects the light source 102 to a supply of electrical power 110. Aconnector 108 allows signals from an imaging sensor (not shown) at thedistal end of the device to be connected to a video or other display112.

In operation, the physician can adjust the supply of electrical power110 to the one or more OLEDs at the distal end of the medical device 100in order to adjust the intensity or illumination wavelength of the lightproduced. In some instances, the power supply 110 may be automaticallycontrolled to illuminate the tissue with a number of differentwavelengths such that images can be obtained with illumination light ofeach wavelength in order to view tissue under a variety of illuminationconditions. Alternatively, the light source may be strobed to obtainimages of moving tissue such as heart valves, etc.

Depending on the wavelength of the illumination light, different imagingtechniques may be used to view or diagnose tissue in the body. Theseimaging techniques include: drug induced or native fluorescence imagingand white light or colored light imaging. In addition, light from thelight source can be used to activate photosensitive drugs, or infraredheat can be supplied to tissue in the body.

FIG. 4 illustrates an embodiment of the invention whereby a medicaldevice 120 has one or more strips of OLED material 122 positioned alongits length. The strips 122 are preferably ruled or otherwise marked withdistance indications. The one or more strips 122 can therefore be usedto gauge how far the device 120 is inserted into a patient. The strip122 may be integrally formed on the medical device 120 or may beseparately formed by a semiconductor or lithographic process and securedto the device 120 with an adhesive or the like.

In the embodiments shown in FIGS. 1-4, it may be desirable toencapsulate the OLED light source with a transparent cover or shield toprevent bodily fluids from contacting the light source.

As will be appreciated, the OLEDs generate more light in a smaller areaand with less heat than that produced by conventional LEDs. The lightproduced may be sufficient to externally view the position of theilluminated medical device inside the body with the naked eye or withexternal imaging equipment.

In some instances, it may be desirable to provide a mechanism forremoving heat from the one or more OLEDs and transferring the heat to apoint away from the patient's body. In one embodiment of the invention,the medical device includes a heat conducting polymer such as thatdescribed in U.S. Pat. No. 6,620,497 assigned to Cool Options, Inc. ofWarwick, R.I., and which is herein incorporated by reference. A headconductive polymer as described in the '497 patent can be used to formthe tubular walls of the medical device or a cover of the medicaldevice. Alternatively, the medical device can include a strip of such aheat conductive polymer material having one end thermally coupled to theOLEDs and another end positioned away from the OLEDs. The striptherefore conducts the heat produced by the OLEDs away from the patient.The heat can be transferred outside of the patient's body or over alarge enough area such that no point of the medical device that iswithin the patient becomes hot enough to cause discomfort or burn thepatient.

Furthermore, the OLED endoscope may include a torqueable pull wire suchas disclosed in U.S. Pat. No. 5,642,736, which is herein incorporated byreference, in order to provide the ability of an operator to bend thedistal tip and to rotate it by torquing the wire or rotating it aboutits longitudinal axis.

While the preferred embodiment of the invention has been illustrated anddescribed, it will be appreciated that various changes can be madetherein without departing from the scope of the invention. For example,although the invention has been illustrated with endoscopes, it will beappreciated that other medical devices such as guide catheters,guidewires, ablation devices, balloon catheters or other devices couldbe equipped with such a light source. It is therefore intended that thescope of the invention be determined from the following claims andequivalents thereof.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined at follows:
 1. A medical illuminationdevice comprising: a tubular member extending from a proximal end to adistal end; a substrate; a first electrode located on the substrate; afirst lead coupled to the first electrode; a first LED, wherein thefirst LED radially surrounds a length of an outer surface of the tubularmember and extends distally of the first electrode; a second electrode,wherein the first LED is directly connected to the first electrode andthe second electrode; and a second lead coupled to the second electrode.2. The medical illumination device of claim 1, further comprising asecond LED.
 3. The medical illumination device of claim 2, wherein thefirst LED and the second LED are spaced apart from one another along thelength of the outer surface of the tubular member.
 4. The medicalillumination device of claim 1, wherein the first LED is an organic LED.5. The medical illumination device of claim 1, wherein the first LED isone of a plurality of LEDs, and wherein each of the plurality of LEDs isconfigured to produce a first wavelength of light.
 6. The medicalillumination device of claim 1, further comprising a second LED, whereinthe first LED is configured to produce a first light having a firstwavelength, and the second LED is configured to produce a second lighthaving a second wavelength, different than the first wavelength.
 7. Themedical illumination device of claim 1, further comprising a heatconductive polymer that is thermally coupled to the first LED.
 8. Themedical illumination device of claim 1, wherein the first LED is one ofa plurality of LEDs, and wherein the tubular member defines a lumenextending through each of the plurality of LEDs.
 9. The medicalillumination device of claim 1, further including one or more lumensextending from the proximal end to the distal end of the tubular member.10. The medical illumination device of claim 1, wherein the first LED islocated longitudinally between the first electrode and the secondelectrode.
 11. The medical illumination device of claim 1, wherein thesecond electrode is located on a distally-facing surface at the distalend of the tubular member.
 12. The medical illumination device of claim11, wherein the second electrode extends around a periphery of thedistally-facing surface.
 13. The medical illumination device of claim11, further including a light source and an image sensor at thedistally-facing surface.
 14. The medical illumination device of claim 1,wherein the first electrode extends circumferentially around thesubstrate.
 15. A medical illumination device comprising: a tubularmember having a proximal end and a distal end, wherein the distal end isdimensioned for insertion into a body cavity; a first electrode locatedat a distal region of the tubular member, the first electrode configuredto be coupled to a supply of electrical power; and a first LED, whereinthe first LED extends distally of the first electrode on the tubularmember, and is configured to illuminate at different wavelengths inresponse to different levels of electrical power provided by the supply;wherein the tubular member defines one or more lumens extending throughthe first LED.
 16. The medical illumination device of claim 15, furthercomprising a heat conductive polymer that is thermally coupled to thefirst LED.
 17. The medical illumination device of claim 15, wherein thefirst LED encircles a length of an outer surface of the tubular member.18. The medical illumination device of claim 15, wherein the first LEDis one of a plurality of LEDs, wherein each of the plurality of LEDs isorganic.